Mosman Oil and Gas said staff has been made redundant following the cancellation of a sale and purchase agreement with Origin Energy Limited.
The decision, which was announced earlier this month, will see only core staff retained to operate the existing permits on a reduced basis.
The company said further reductions are anticipated with executive directors also capping the cost of their services in the current low oil price environment.
In a statement the company said it remains in a “sound” financial position, with in excess of $5million in cash.